A new version of this article has been published on the Internet. It is based on an earlier version of the same article that was published on January 1, 2013.
It has been updated since then to include new information. The original version was published by the author on January 2, 2013, on the same day as this article. For more information on this article, please visit: http://www.cnn.com/2013/01/02/08/29/17/science/features/science-and-environment/index.html#storylink=cpy.